Stephen R. Waldee (c) 1990-2008 - All Rights Reserved

The Discovery of the "Horsehead Nebula" in the 19th Century, and other developments related to the study of faint and dark nebulae by eye and early astrophotography.

INTRODUCTION

Exactly one hundred years ago [written in 1990] in the 1890 Harvard College Observatory Annal, the astronomical world at large was routinely informed of the discovery of what we now regard as one of the most beautiful objects in the heavens, the unique and mysterious dark nebula known as ''The Horsehead.''

During the next several decades, it was to capture the attention of some of the world's leading celestial scientists and theorists, and would eventually become familiar to the interested public from images of its striking beauty that required the machinery of the greatest telescopes, and the patience of the most dedicated astrophotographers.

For many decades the prey of only the elite of professional astronomers and photographic technicians, the Horsehead can now be captured by the dedicated amateur visual astronomer.  Thanks to the efficiency of today's precision-made yet inexpensive coated optics, narrowband nebular filters, and fast film emulsions, the Horsehead's fascinating shape and dark contrast may be enjoyed by means of simple, modest equipment well within the budget of many amateurs who want to challenge themselves to one of the ultimate tests of astronomical skill.

The author served for two years as a telescope salesman, demonstrating rows of shiny new Schmidt-cassegrains in sight of the famous David Malin UK/Australian telescope poster of the Horsehead. A frequent customer query about the visibility of this nebula, so clear and sharp in photographic time exposures, yet so evasive to the visual observer, led the author and a small group of diligent amateurs to undertake our project:

 (a) to track down the history of historical sightings and photos; 

 (b) to test the visibility of the nebula in the smallest-aperture optics under varying sky conditions; 

 (c) to attempt to produce professional quality pictures with the simplest equipment, and 

 (d) to uncover the seemingly-lost origin of the popular nickname of this beautiful object.

In pursuing his detective work, the author began to wish he were an astronomically-minded Hermann Melville, so exhausting yet exhilarating was the search for this elusive dark horse, as tantalizing as the great white whale was to Captain Ahab! In seeking answers, we encountered many unexpected episodes that may overturn a few misconceptions and inaccuracies, and will at last do justice to a few historical figures who have not received their full credit.

This paper will cover the Horsehead's discovery, and initial study, during the 19th-century transition from visual to photographic astronomical observation, from the perspective of an amateur astronomer who, as a volunteer at Lick Observatory, was privileged to study the great organization's archival material in quest of knowledge of the techniques used by professional astronomers at the eyepieces of the great telescopes in the pre-photographic era.

THE LURE OF THE NEBULAE

''Hier ist wahrhaftig ein Loch im Himmel'' -- here is truly a hole in Heaven -- cried Sir William Herschel, the greatest astronomer at the end of the eighteenth century and the possessor of the world's largest telescope, of 40-foot focal length and 48 inches of aperture. While sweeping a star cloud near the borders of the constellations Scorpio and Ophiuchus, Sir William thus cried out in astonishment as a deep black spot drifted into the field, otherwise crowded with myriads of stars and nebulosity that only his gargantuan telescope could reveal.

Bright nebulae, such as the great cloud in Orion, (discovered by the Frenchman Peiresc in 1610, a scant few years after the first simple spyglass telescopes were invented), (2) had slowly accumulated in number as instruments, observers, and sky charts improved by the 1700s.

Yet professional astronomers were most likely to study positions of the stars for aid in surveying, time-keeping, and determining locations of the planets and Moon; (3) expenditures for such studies could always be justified by governments for their practical benefits in navigation, even warefare.    

Owen Gingerich writes that "to the astronomer of 200 years ago, it was the static, nondescript nebulae that were trivial." (4) But a holdover of earlier superstitious times was an avid interest in the nebulae that moved across the sky: comets. The first nebular catalog, an amateur pursuit compiled by Messier and Mechain, listed fuzzy-looking patches not to be mistaken for new comets, and described many objects known well to earlier observers; even the first entry M1, the ''Crab'' nebula, was found previously by J. Bevis. (5) 

William Herschel had begun to turn his newest large reflector telescope on these mysterious patches of light during the year that Messier published the first 68 of his nebulous-object discoveries. (6) In small or defective instruments they appeared as unresolved smudges; with better optics, some of the images were clarified into star clusters or chance stellar- alignments, called asterisms; yet many failed to coalesce into point-sources of light. Thanks to his efficient telescopes, it was solely Herschel's opportunity to discern and catalog some 2,000 nebulae and star clusters, many not seen again for the large part of a century. Ultimately he was able to construct his 48-inch ''speculum'' -- as reflectors were known, named after the metallic command of their shiny mirrors.  

Herschel determined that only 67% of available light was reflected by a freshly-polished speculum, as used without a diagonal secondary in the unobstructed Herschelian telescope. (7) From this we can calculate that before tarnish robbed the mirror of its luster, the great 48-inch instrument of 1789 was equivalent to about a 42-inch contemporary mirror, which might be coated to prevent more than a 12 percent light loss from its aluminum surface. (8) 

A nebula that had a fuzzy, cometic appearance in Messier's 90-millimeter aperture refractor (9), would be seen by Herschel as a cluster of hundreds of tiny stellar points, leading him at first to suspect that all nebulae could be thus resolved. (10) But scrutiny with his two largest telescopes convinced him that even his instruments could not discern stellar structure in what he called "extensive diffused nebulosity.'' (11) 

In his paper on ''The Construction of the Heavens'', read to the Royal Society in 1811, Herschel defines nebulous matter as "those substances which give out light, whatsoever may be their nature, or of whatever different powers they may be possessed." (12) He reasons that ''faint milky nebulosities'' that cannot be resolved into stars must be deeply distant in space because of their tenuous and dim natures; the beginning and ending of their milky luminance is uncertain, as the objects drift slowly through the field of his telescope.

Herschel reports that from the years 1783 until 1802, he has assembled a table of 52 areas of the sky that are full of this diffused nebulosity: ''the depth or third dimension of may be far beyond the reach of our telescopes.'' He adds furthermore that such faint and extended milkiness in the skies "can only be perceived by instruments that collect a great quantity of light .'' (13) 

The visual stellar limiting magnitude of the modern equivalent to Herschel's mirror would be about  17th magnitude; however, since the speculum metal rapidly tarnished , typical performance has been estimated to be from 14 to 15-1/2. (14) Herschel should have been able to see many of the same faint objects that may be readily photographed today by an amateur's commercial fast refractor or Schmidt-Cassegrain telescope; thus it comes as no surprise that he perceives ''Diffused milky nebulosity'' the general region of the Horsehead, labelled as no. 25 in Herschel's table of sites. (15) 

Due to its massive mounting, the 40-foot telescope required a sturdy operating assistant, and set-up time was long and prohibitive, consuming many precious hours of the rare clear skies infrequently available in the cloudy English climate; so Herschel preferred using his 20-foot instrument of 18.8 inches' aperture, which could be controlled solely by himself. By mean of ropes operating pulleys and wheels, Herschel could rotate the tube in slow 12- to 14-degree sweeps of azimuth during his sky surveys.

Methodical and precise in all aspects of observing, he determined that his eyesight was most efficient when fully dark-adapted, and learned to don a black hood as a stray light shield.   Proper powers of magnification  were carefully chosen, Herschel explaining that ''Objects are viewed in their greatest perfection when, in penetrating space, the magnifying power is so low as only to be sufficient to show the object well...the injudicious overcharge of (inappropriately low or high power) will prove hurtful to perfect vision." (17)

As Herschel calculated that his dark-adapted pupil should admit a light cone of 0.2 inches (about 5 mm) diameter, (18) we may, by simple division of the 18.8 inch aperture of the 20-foot scope, determine that the most efficient power permitting his eye to utilize the full area of the mirror would be about 92 diameters of magnification. Modern deep-sky observers will agree that this is an excellent power for resolving globular clusters and discerning the outlines of many planetary nebulae and galaxies, while being too high for encompassing the largest nebular loops (such as the ''Veil'' in Cygnus) or closest spiral galaxies (like M31 or M33). With his two largest-aperture scopes, Herschel seldom exceeded 200 diameters' magnification during nebular studies, in order to preserve the widest field concurrent with highest contrast for picking out faintly luminous regions against the sky background.

When sweeping for nebulosities, Herschel employed a field of view that was 15 arcminutes in diameter, and found such large vistas of milkiness that "the abundance of nebulous matter diffused through such an expansion of the heavens must exceed all imagination."(20) His theories of nebular development, based on extensive observation and differentiation of types of nebulously, led him to hypothesize that these diffuse patches represented the primitive state of nebular birth, leading eventually to the relatively defined structures of what we now call the planetary nebulae and galaxies.

He held that most nebulosity was self-luminous, was subject to gravity, and could be found in condensed or elastic form; some of the substances possessed ''the power of arresting light in its passage." (21) 

It was the rich field of nebulosity and innumerable faint stars around Rho Ophiuchi that contained the suddenly-encountered dark region that so startled Herschel, who returned to it repeatedly, unable to decide from mere observation if it was an obscuring patch or a indeed a starless ''hole the Heavens.'' (22) 

Herschel had previously rejected a theory that globular clusters were, in effect, glimpses of rich star fields popping into view through 'tunnels' leading outwards, through an obscuring medium. Because of the unlikelihood of finding such a multiplicity of bright holes all pointed straight at the earth, Herschel was troubled that his dark holes were also a flawed conception, but observational astronomy could offer no better explanation.

According to a paper by Dr. Elizabeth Lada, professor of astronomy at the University of Florida, William Herschel "apparently did not attach too much greater significance to this... However, [his sister] Caroline appears to have guessed that this... held a potentially greater significance." A half-century later, using observations made in South Africa by her nephew John and the large body of her brother William's data, gathered with her assistance, Caroline Herschel compiled the first catalog of dark nebulae (containing 33 entries, cited in a 2006 article by Dr. Michael Hoskin of Cambridge University, a scholar of Caroline Herschel's scientific work.) Dr. Lada states that "It wasn't until the early twentieth century that the work of Barnard and Wolf conclusively demonstrated that these startling vacancies in the sky were true astronomical objects-- dark obscuring nebulae and it took another half century until astronomers proved them to be the birth sites of all stars and planets in the galaxy, amply confirming Caroline's intuition concerning their importance in the pantheon of astronomical objects." [update from recent research, added 7/07.]

A century was to pass after Herschel's first perplexing observation before Edward Emerson Barnard would accumulate the evidence to persuade his fellow astronomers that these mysterious spots were not holes, but were rather actual obscuring masses of real matter. The Horsehead can surely be described as one of the most beautiful and definite of these dark tenuous bodies, and it occupies a place of honor at the very center of the investigation that follows.

THE PIONEERING PICKERING

Astronomy in the middle decades of the nineteenth century was benefited by the manufacturing advances of the industrial revolution, leading to the creation of ever more perfect telescopes capable of great accuracy, far surpassing even the precision of Herschel's measurements. The Fraunhofer achromatic retractor, aided by the stability of the German equatorial mount with its sidereal tracking by means of a clock drive, ushered in nearly a century of development that would culminate in the great 40-inch aperture Yerkes refracting telescope, completed in 1897. (23) 

Following the lead of Fraunhofer, the firms of Merz and Mahler (Munich), Alvan Clark (Cambridgeport, Massachusetts), Thomas Cooke (York, England) and Howard Grubb (Dublin) crafted the finest refractors of the period. The Merz and Mahler telescopes of 15-inch aperture -- one made for the Pulkowa Observatory in Russia, the other for the Observatory of Harvard -- were considered to be especially superb. (24)

The precision of these refractors, and of related instruments designed as transit devices, led them to be utilized for the careful measurement of stellar positions, as astronomy grew increasingly dominated by star counters and number crunchers. We have but to contrast Herschel's 1789 visual discovery of Uranus by means of a systematic visual search, to the theoretical, numbers-dominated work of Adams and Leverrier nearly a half- century later in the discovery of Neptune in 1846, to understand how an almost relentless application of mathematics and the scientific method had changed the orientation of astronomy.

But surpassing even the advances of the precision metal-fabricators' art, a new invention would eventually render obsolete all professional visual astronomy. As soon as photographic apparatus was sensitive enough to register first the light of the Moon in  1840, the sun's disk in 1845, and then the image of the bright star Vega in 1850, astronomers grew interested improving their results with the permanent records provided by photographs. Sir William Herschel's son John urged the Royal Society to establish a photographic program in 1855. (25) Even the conservative Astronomer-Royal Sir George Airy was impressed! The Lick Observatory's Mary Lea Shane archives contains a precious document (delicately handled in some awe by this writer!): an 1851 letter from Airy eagerly inquiring about the latest technical details in stellar photography.

Though the world's greatest observatory refractor telescopes outnumbered reflectors nearly 4 to 1 in Professor Simon Newcomb's 1882 accounting in a popular book on astronomy, successful reflectors -- from Lassell's 24-inch to the Earl of Rosse's 72-inch leviathan -- offered much greater light gathering powers. (28) Furthermore, the reflector's freedom from false chromatics better aided the early astrophotographers in achieving accurate focus and clean images.

The first photograph of a nebula was made by Dr. Henry Draper in 1880, using a 51-minute exposure with an ll-inch Clark refractor. Only the central part of the great Orion nebula was registered, showing fewer stars than a 6-inch aperture telescope could reveal to the eye. The far greater efficiency of the newer ''fast'' 36-inch aperture f/5 reflector of Dr. Ainslee Common, despite its quick-to-deteriorate silvered surface and fussy, cumbersome mounting, was employed a mere three years later to secure an excellent picture of the same nebula in only 37 minutes. while recording stars invisible in the eyepiece. (27) 

When Wilhelm Tempel's visual discovery of the Merope nebula in the "Pleiades" (M45) in 1859 was questioned by other visual observers, it was only through the 1885 photograph produced by the Henry brothers of France that the claim was proved conclusively. (28) Photography could unambiguously settle disputes, and advance the discovery of new objects in the sky.

THE INVENTIVE PICKERING BROTHER

In 1878 the 20-year-old William Henry Pickering would have his first exciting astronomical experience, measuring the polarization up the sun's corona during an eclipse. (29) Born on February 15, 1858,   this brilliant young man from a famous Boston family would display voracious and wide-ranging scientific interests. Graduating from the Massachusetts Institute of technology in 1879, he first taught physics there while working with early experimental telephonic devices in Boston. Interest in the skies lured William away from electricity, and finally in 1887 he became Assistant Professor of Astronomy at Harvard observatory, where his brother Edward Charles Pickering (1846-1919) had been Director since 1876. (30) 

W. H. Pickering had specialized at M. I. T. in exploring the characteristics of photographic films, and in 1880 he discovered a difference in sensitivity between normal outdoor sunlight and the spectrum of indoor gaslight, leading to the development of ''indoor/outdoor'' film emulsions. In 1883, the younger Pickering published results demonstrating that photographs could be made in the infra-red light that Herschel had discovered at the turn of the century. (31)  

As an avid amateur photographer, Professor Pickering produced a succession of rapid-exposure shots of a horse in motion (an idea currently very much in the air, to satisfy a $25,000 bet by Gov. Leland Stanford that a horse races at full gallop with all four legs repeatedly raised off the ground -- resolved by publication of Edweard Muybridge's famous photographs from 1878.) The clever amateur photographer Pickering independently accomplished one of the first steps that would lead eventually to the development of the 'movies'. (32) 

Brother Edward C. Pickering was a tireless worker in the field of stellar photometry, and is said to have personally made over 1.5 million photometric readings. (33) In the year 1887, on the basis of Williams successful photo of the Great Nebula in Orion (using a small camera lens and the new dry plates), Edward put William in charge of photographic investigations.

The Harvard College Observatory's impressive collection of nearly 500,000 plates of the sky eventually resulted from William's recommendation to his brother of pursuing a careful photographic celestial survey program. (34) In the next four years, culminating in an elaborate official report by William published 1895, extensive studies were made under the younger Pickering's direction which led to the firm establishment of many principles of astrophotography still accepted today. (35) Pickering's impressive report contains convincing conclusions on the merits of doublet lenses versus reflectors of various photographic focal ratios and apertures; requirements for telescope tracking clocks and guiding techniques; the limits of photographic resolutions; details of preparation of plates, development, enlarging and printing; and the enhancement of contrast for reproductions of original negatives. 

In a study he called ''Quantitative Photography'' Pickering details extensive experiments on improving the standard photometric light source (being flame-driven in the days before the use of the incandescent electric bulb), methods of measuring sensitivities of plates, preventing the artifacts of ''halation'' (circular reflections around bright stars), and standardizing exposures for production of reliably comparable survey photos: all outlined with admirable precision.  Of special use to his brother's program of stellar photometry is William's production of the "Standard Square", a means of securing graduated and calibrated photographic magnitudes by comparing sky photos to test plates, exposed at different increments of intensity through 1-centimer squares punched into an opaque mask.

Sky-fogging from artificial light pollution caused by gaslight and the new-fangled electric lamps is explored under varying focal ratios and exposure times. And the failure of the so-called "Law of Reciprocity" (wherein lengthy exposures deepen images at a nonlinear rate of exposure time) is examined, with a proposed "Time Correction'' of the plates. (36) This last is all the more remarkable since Abney 1894 and Schwarzschild in 1900 are considered by authorities to have confirmed "low-intensity reciprocity failure", and Pickering is not credited with his accomplishment. (37) His efforts to secure fast exposures even encompass considered by authorities to efforts to secure fast exposures even encompass experiments in "hypersensitizing" film by a technique now sometimes called pre-exposure, which a brief exposure of the plate to an overall luminance increases the photographic speed of the emulsion. (38) 

In contrast to his earlier experiments with the long waves of infra-red light, W. H. Pickering now explores the best techniques for photography of the "actinic rays" of short wavelengths (so named in those years after the radiation in the violet and ultraviolet part of the spectrum produced by such substances as the radioactive mineral actinium.) Careful determination of the focal plane at different wavelengths of light is measured with the various Harvard telescopes and lenses, and the ''actinic constant" -- or percentage of transmission of short-wave light -- is calculated for the reflectors and refractors employed to insure standardized exposures. (39) 

The orientation of the sky's geographical coordinates on plates, the epoch chosen for measuring objects, and the sizes of star images are further standardized, (40) so that the Harvard photographic efforts may long be used to provide accurate comparative data, despite future improvements in equipment and techniques.

In this painstaking work, Professor William Pickering is assisted by the diligent E. S. King, (41) later to be renowned for his publication of "A Manual of Celestial Photography", currently in print, establishing the accepted formulae for calculating the clock tracking rate adjustments to compensate for atmospheric refraction at varying declinations. King's compensations were so accurate that by 1899 he was able to use the Harvard 11-inch Draper refractor for a 2-hour unguided picture of the globular cluster M13, obtaining stellar images a mere 2 arcseconds in diameter (compared to many extant contemporary plates in which whole clusters were depicted merely as smeared blobs.) (42) 

During these years of initial investigations, William's boundless energy and enthusiasm for experimenting with celestial photography under all possible conditions led his brother to send him on expeditions to test results under better skies than those available in Cambridge. First Pike's Peak in Colorado, and then ''Wilson's Peak'' near Los Angeles -- now, of course, the site of the famed Mt. Wilson Observatory -- yielded fainter images at shorter exposures, enabling the use of extremely modest apertures. (43) 

William wrote in the January, 1990 edition of "The Sidereal Messenger" (a popular science magazine of the time) that his expedition to Mt. Wilson during the current winter had produced important discoveries in new photographs of the Orion nebula, made with a mere 2.6-inch aperture lens with a focal ratio of 3.3. The excellence of the sky permitted a faster lens than employed at Harvard:

  "an excellent test...not of the instrument or the steadinessr but of the clearness of the air, and the blackness of the sky. Owing to recent advances in stellar photography, this matter of sky illumination has assumed considerable importance, and it is very doubtful if any of the fainter nebulous extensions here described can be photographed at any Observatory located in or near a large city. This is due undoubtedly in part to the gas, but chiefly to the electric lights, which illuminate the slight haze found in the sky of nearly all localities with an almost imperceptible light, but which is nevertheless, very destructive to the fainter detail shown by our most sensitive plates when used with long eposures.''

On his Mt. Wilson photos, Pickering secured stars as faint as the 12th magnitude, as well as extensive areas of nebulosity in the constellation of Orion, streaming from the stars Theta and Zeta in the belts, with loops throughout the central area of the constellation. "This nebula is shown by three different exposures and is very distinctly marked.''(44) 

The same nebula would soon be independently discovered by Edward Emerson Barnard at Lick Observatory, and would greatly influence the later investigator's future photographic exploration of the sky.

In the seminal Harvard College Observatory report on photography of 1895, W. Pickering outlines studies of the Moon and the planets, but most especially of the Orion nebula, comprising the important goal of achieving discoveries by camera that could not be detected by eye.  By then over 3,000 plates had been exposed, and it had been determined that the fast f/5.5 photographic doublet of the 8-inch aperture Bache astrograph was ''especially adapted to charting, on account of its large field and scale" and would photograph nebulae as faint as those captured by a reflector. (45) Celestial photographs would now be capable of recording data of faint stars that were difficult to determine by eye by the most careful examiners: in an exposure of something less than 3 hours with the Bache doublet, stars were recorded that could be faintly seen in the renowned Harvard 15-inch refractor. (46)

Accordingly, plates of the Orion constellation were new stars not previously cataloged, including some suspected variables, and to obtain images of the famed Orion nebula that could be compared to earlier drawings, as well as the photos obtained by Draper and Common only a few years earlier, to study the possibility of changes in the nebula. (47) 

The resulting images would be used to produce an ''isophotal'' or topographical charts of the nebula's extent, carefully measuring areas of differing luminosity on the original plates through a brass sheet perforated with holes the sizes of Standard Squares. That W. H. Pickering was firmly in charge of the photography project is established by his comments on P. 57, apologizing that once it had been necessary to employ a substitution plate taken in his absence, owing to an accident causing damage to the original. (48)

The Standard Squares made possible a more perfect estimate of luminosity of portions of the nebula than any visual technique had permitted; by comparing standardized plates made with different instruments, Pickering could estimate a difference of brightness of about 700 units, from the densest areas near the "fish mouth'' or ''Huygenian'' area, to the outlying tendrils faintest light.

   "If the nebula be taken with a comparatively slow lens and long exposure, much greater contrasts are obtained, and the general effect is less pleasing. This is merely another illustration of the phenomenon to correct which we have applied the so-called time-correction, and it must explain the disappointment that many astronomers must have experienced when they came to examine their long exposure plates, and found so little on them not shown by shorter exposures.'' (49) 

This lesson had apparently not been learned as late as 1900 by the British astrophotoorapher Dr. Isaac Roberts, who figures prominently in the Horsehead story (as E. E. Barnard's criticisms of Roberts' pictures will later relate.)

We turn at last to the central issued the discovery of the Horsehead nebula, and refer to the Harvard College Observatory Annal published in 1890. Each new plate -- taken by W. H. Pickering and his assistants E. S. King, Robert Black, and A. E. Douglass (50) -- was breaking new astronomical ground, as the Observatory's announcements of discoveries would reveal. The project of carefully measuring and cataloging all the new stars and objects was undertaken with the same methodical skill as demonstrated by the professor's work at the telescopes and cameras, requiring an extensive program of plotting and enumerating to be carried out as each plate was secured. (51) 

Popular and respected modern astronomical reference works such as "Burnham's Celestial Handbook" (52),  written by a staff member at Lowell Observatory, often cited by many other volumes and articles, fail to give W. H. Pickering his due credit for producing the first photographs of the Horsehead nebula, and the present author presumes to suggest why. The paper announcing the discovery of what we now call the Horsehead, ''Detection of New Nebulae by Photography'' is included in the Harvard College Observatory Annal, Volume 18. It is presented without attribution, in the publication edited by Edward C. Pickering, the director. The unidentified author refers to his previously published discussion of the advantages of the wide field doublet, suggesting conclusively that it has been written by the photographic expert, brother William. Furthermore, the younger Pickerings's assertive, fluid, and detailed style is clearly present throughout; indeed, the famous British astronomer E. Walter Maunder credits the paper to W. H. Pickering in the Journal of the British astronomical Association, Volume I, published in 1891. (53) 

W. H. P. himself covers exactly the same ground in his later signed paper that comprises the entirety of the Harvard College Observatory Annal for 1895, quoted extensively in paragraphs above.

We come now to a most remarkable and unexpected episode in the saga. The Orion nebula plates taken by Pickering with the Bache telescope were given to a staff member, one Mrs. Williamina Paton Fleming, to examine, categorize, measure, and catalog new objects. 

Williamina P. Fleming, courtesy of Harvard College Observatory Archives

According to Dr. Martha L. Hazen, the Curator of Historical Photographs at the Harvard College Observatory,

Mrs. Fleming (1857-1911) came to Massachusetts from her native Scotland in 1978 and went to work early the following year in the household of Dr. Edward C. Pickering -- as his second maid!  Impressed with her accuracy and persistence, Director Pickering hired Mrs. Fleming to work part-time at the Observatory in 1879, and from 1881 until the year of her death she was a staff member, (54) a very good example of one of the early unsung women the male-dominated world of astronomy. Her portrait reveals an extraordinarily determined countenance, even for those formal times! In another photograph Mrs. Fleming is shown sternly supervising the women "computers" at the Harvard Observatory, with Director E. C. Pickering looking on (perhaps with the trace of a patient fatherly smile on his countenance.)

Beginning on June 27, 1888, (55) Mrs. Fleming took each of the Orion plates, placed it on an illuminated frame at an angle of 45 degrees, and studied all portions with a magnifying glass to find any suspected nebulae recorded during the exposure. Each object's coordinates were measured, referred to the star chart of the standard Bonner Durchmusterung reference published in 1863, plotted at the same scale as the new Harvard photographs. In the HCO Annal publication a table is given comparing the results of searching through four plates, covering the area, with a fifth plate used to check the results of the others. The "A" rating given to the Zeta Orionis nebula qualified as 'unmistakable' on all the plates taken of the region. (56) 

Director E. C. Pickering, with Williamina P. Fleming (center) supervising the "women computers" at HCO. Evelyn Leland seated (front); Antonia Maury at left. Courtesy of Harvard College Observatory Archives

The official discovery plate that registered the Horsehead nebula was number B2312, taken with the Bache telescope in Cambridge on February 6, 1888, with an exposure time of 90 minutes. (57) On that plate, Mrs. Fleming recorded a nebulosity -- listed as No. 21 in her table -- described as follows: "A large nebulosity extending nearly south from Zeta Orionis for about 60 minutes. More intense and well marked on the following side, with a semicircular indentation 5 minutes in diameter 30 minutes south of Zeta. Good plates of this region show this object, and it has been used here as a test for some time. Attention was called to it in a letter of March 28, 1887, describing copies of some of these photographs sent to the Astrophotographic Congress of 1887..." (58)

A further accounting of nebulae discovered on Harvard photographic plates is published in the Harvard College Observatory Annal, Volume 60, of 1908. There in the table on p. 149, entry No. 62 lists the nebula as having been discovered by "W. P. Fleming".  (59) 

So, as far as the Harvard College Observatory is concerned, the official discoverer of the nebulosity containing the Horsehead was a woman, and one who been promoted from housemaid to observatory staff member! 

The conclusion to the earlier 1891 Harvard paper states that 12 cited nebulae not plotted in Dreyer's New  General Catalog were probably new. Since only 1/4000th of the sky was covered by these plates, the proportions of known nebulae were correct ''we might expect to discover four or five thousand such objects by photographing the entire sky." (60)

Such project was of course undertaken, and the paper's prediction proved to fall far short of the mark, judging from the results that were obtained only a few years later with the great Crossley Reflector at the Lick observatory! 

Four years later William Pickering elaborates on the nebulae discovered on these plates in the 1895 Harvard College Observatory Annal. A copy of Plate B2312 is published, and he states that lantern slides of it were widely distributed just after was made February of 1888. The Orion belt stars Iota and Theta are found to be connected -- 

''by a long nebulous streak, and another nebula, that surrounding C Orionis, is shown at the top of the figure...near the top of the figure, two of the stars of the belt, Zeta and Epsilon, are shown, the former partially enveloped in a large nebulous mass [NGC 2024] clearly visible on the east, and to which is attached a streamer extending towards the great Nebula. In this streamer is a well-defined and rather striking notch [the "Horsehead" - our italics]... In the figures so far described, are shown nebulous masses of which a large part, more or less imperfect, can in each case be seen visually." (61) 

Pickering finds that unlike the great Nebula in Orion with its deep incurving branches, well developed on the inside but vague at the outer extremities, ''when we come to the nebula surrounding the star Zeta Orionis we find matters reversed, and the notched side is turned away from Theta indicating another and stronger outside influence." (62) 

Later, Professor W. H. Pickering reports examining the Bache plates to compare nebulosities shown on his Mt. Wilson photos, and finds that since the new negatives registered stars 3 magnitudes dimmer, stars of the 14th and 15th magnitudes are distributed rather unevenly throughout the region. ''Whether the fainter stars are really absent in this region, or whether their light is absorbed by non-luminous gas, it is of course impossible to tell.'' (63)

All of the objects confirmed by the team are sent by Dr. E. C. Pickering to the famed Dr. J. L. E. Dreyer, compiler of the New General Catalog, published 1887 and containing all the nebulae known to the end of that year. 

Dr. Dreyer lists Mrs.Fleming's large 60-minute notched nebulously as "No. 434" his updated ''Index Catalog" and presents his new collection of nebulae, incorporating the Harvard findings plus those of ten other individuals and observatories, to the British Royal Astronomical Society. 

To further confuse the issue of the discovery of IC 434, Dr. Dreyer catalogs the object not with Mrs . Fleming's name -- the good lady being at the time unknown to most of the world's celebrated astronomers -- but 1ists under the co1umn of observers for all objects -- confusingly -- simply ''Pickering.'' (Thus, one eminence in Europe pays tribute to another one in America.) 

The following day Dreyer addresses the Royal Astronomical Society, explaining the new entries to his ''Index Catalogue of Nebulae'' with the perhaps apologetic dismissal that most are "very faint and minute and doubtless represent but a very small part of the innumerable host of similar objects which are within the reach of our largest telescopes...the majority these new nebulae cannot compare in interest with those cataloged in earlier years...the number of observers to whom  this will be of use will naturally be a comparatively  limited one." (65)

Little could the good Doctor guess that the study of astronomy would soon turn from the rather arid territory of calculating and infinitely refining stellar positions, to the fruitful field of measuring the entire extent and substance of our universe by means of these insignificant, often spiral-shape, smudges! We must Dreyer with realizing that the "extensive and diffused nebulosities detected by means of photography by Mr. Barnard and Professor Max Wolf" were, after all,  important: they could corroborate the great visual work of Sir William Herschel. 

Dreyer continues, ''The fifty-two regions found by William Herschel to be more or less 'affected with nebulosity' ought to be reexamined by means of photography.''(66) And that is precisely what the amateur astrophotographer Isaac Roberts, a future participant in the Horsehead race, was currently doing with his 20-inch aperture reflecting telescope in the Sussex inlands.

We  can summarize the results of the Harvard Observatory's photographic program, at least with respect to the Horsehead nebula findings up to 1895, as follows: 

1. W. H. Pickering persuades his brother E. C., the Director to undertake a systematic study of celestial photography, and to begin a sky survey.

2. The younger Pickering explores virtually all concepts of astrophotography, and perfects possible techniques to aid his brother's photometric program and to discover new objects within the grasp of Harvard's equipment.  His examination of the craft represents the absolute state-of-the-art of celestial photography in the late 1880s, describing some techniques that are still currently employed.

3. The Orion nebula is chosen for special study, and a series of plates is undertaken, starting in 1887, expanding on test photographs of the region earlier made by W. H. Pickering. Nebulous regions are shown on early test plates, and the curious streamer south of Zeta Orionis is communicated by letter to the 1887 Astrophotographic Congress. By early 1888, over 3,000 sky plates have been made by Harvard College Observatory.

4. On February 6, 1888, an especially good plate of Orion, No. B2312, is taken by Pickering, and lantern slides are distributed to the public .

5. Four months after production by W. H. Pickering of this fateful discovery plate containing the Horsehead, Mrs. Fleming begins the task of cataloging the new objects found on the Harvard plates. The nebula south of Zeta, containing the ''notch'' we now call the Horsehead, is cataloged on June 27, 1888, with Harvard's official publication listing W. P. Fleming as ''discoverer.'' (87) 

6. E. C. Pickering sends the findings of new nebulae to Dr. Dreyer, who presents his Index Catalog, containing Harvard's nebula No. 434, to the Royal astronomical Society.  Dreyer publishes the IC 434 nebula discovery, crediting ''Pickering'' -- not his employee Mrs. Fleming -- as ''observer."

7. W. H. Pickering's own report on Harvard's photographic investigations is published in the HCO Annals, containing his procedures and comments. Of the ''nebular streak'' that comprises IC 434, he makes special note of the striking "notch", believed at the time to be an indentation in the stream of luminous matter. He hypothesizes that, owing to the noticeably irregular distribution of the faintest stars in the area, ''non-luminous'' masses may be present.  Thus, the prescient Pickering makes an early and valuable observation about a phenomenon to become critically interesting to 20th and 21st- century astronomers: dark matter.

Most of the events described above were pieced together chronologically by the present author from documents in the Lick Observatory Mary Lea Shane Archives, and from the magnificent UC/Lick Observatory astronomical library in Santa Cruz (comprising the great works on astronomy that the Observatory's first director, Professor E. S. Holden, and his successors collected since the founding of the observatory in the latter part of the 19th century.)

As the present author worked his way from one document to the next, his anticipation mounted as the story began to unfold. A great moment was at hand when he asked by phone for Dr. Martha Hazen, the Harvard College Observatory archivist, to look for the historic plate No. B2312.

After only a brief moment, Dr. Hazen pulled the plate from its place in the neatly-cataloged Harvard files. The jacket had apparently been replaced since 1888, and was later labelled with words to the effect that was an ''Historic Plate - Contains the Horsehead.'' It was Dr. Hazen's impression, upon drawing the plate from its envelope, that the Horsehead region stood out dramatically on the plate, and that it could have been spotted as soon as the photograph had been developed.(68) Sad to say, the only copy available to the present author, at the time of this Internet publication, is merely a cruder photocopy of the 8x10 print sent to him from Harvard; the Horsehead dark region, being merely a change in the background gray level, was not well registered on the copying machine, and still fails to stand out even after reprocessing, compared to our clear recollection of the print and slides of it that we showed during many astronomy club talks in the early 1990s.  (That material still resides somewhere in the bowels of Kalmbach Publishing Company's storage vaults and has failed to materialize by the time of the preparation of this web page; so our scan of the photocopy will have to suffice.)

Despite the passage of a century, the presence of a few photographic defects such as the bright halation rings around stars, and a few smudges, the beauty of the constellation was well-captured in the original, surprisingly fine plate, showing the elaborate tree-like aureole of NGC 2024, the fuzzy star NGC 2023, the softly undulating luminance of IC 434, and of course the dark protruding ''bay'' (as it came to be known early in the next century.) We can assume with some certainty that the Horsehead's notch was seen long before Mrs. Fleming officially recorded Harvard College Observatory's publication.

This chapter must conclude with further notes about William Pickering. The distinguished scientist took his considerable skills and Harvard's equipment -- and irascible, contentious personality! -- to Peru and finally Jamaica, establishing an observatory he would occupy, essentially by himself, for the rest of his years. Along the way, he mounted the 24-inch Alvan Clark refractor that Percival Lowell had purchased for his own Flagstaff Observatory, and turned from photographic pursuits back to the techniques of visual observing. Yet, his greatest discovery was made in 1899 by the photographic process, when he found the ninth satellite of Saturn, which he named Phoebe, on plates taken at Harvard's observing station in Peru. 

The "Mars mania'' of the era, stimulated by much talk of Professor Schiaparelli's canals, found W. H. Pickering a central participant. Visual examination of the evanescent surface markings were interpreted by the Harvard astronomer as clear evidence of the presence of water, and even large tracts of vegetation. (70) Lowell appropriated many of Pickering's ideas, and developed them into outlandish theories of huge, scientifically sophisticated Martians, cultivating their arid soil with what precious fluid they could drain from the polar ice caps.  (71)

Pickering's next fascination was the earth's satellite, and his monumental photographic volume "The Moon" was published in 1903. Unable to restrain his creative imagination (in contrast to the soberer Edward Barnard and other cautious observers of the era), Pickering was quick to interpret his sightings of so-called 'transient lunar phenomena' as certain evidence of a tenuous atmosphere, water vapor, snow or hoar-frost, even organic life: something resembling vegetation was seen "coming up,  flourishing, and dying, just as vegetation springs and withers on the Earth." He concluded that there were undoubtedly "real,  living changes--changes that cannot be explained by shifting shadows or varying vibrations of the lunar surface." (72) 

Through it all, conservative academic astronomers sometimes huffed in displeasure, especially those fortunate enough to employ instruments more powerful and accurate than those of Pickering. An example is found in the great Martian ''canal'' dispute: though Pickering, Lowell, and Douglass (not to mention Schiaparelli and many others) discerned glimpses or "revelation peeps" (73) of sharp linear markings, Barnard at Lick Observatory could resolve the Martian "lines" into myriads of detached dots and mottled patches with the superb 36-inch refractor, determining that the artifacts were spurious -- the present author was thrilled to hold and examine Barnard's own private drawings done at the great Mt. Hamilton instrument, sent to his mentor Simon Newcomb but not published in public at the time, as Barnard was loathe to be drawn into the controversy with Lowell and Pickering. (74)

Ironically, after his Harvard College Observatory photographic program was well underway, W. H. Pickering seemed to stray from reasoned scientific pursuits into the dangerous matters of subjectivity, vowing that ''the human eye must reign supreme." (75) From our vantage point at the end of another century [written in 1990],  Pickering's hair-splittings on the questionable evidence obtained from fleeting glimpses with small telescopes seem as outdated and contentious as certain medieval theological arguments.

Isolated in his Jamaican retreat and venerated as the great ''Professor'' by the locals, he grew somewhat preachy in advising the younger astronomical community: sternly recommending that the Lick 36-inch refractor should be modified by the addition of ventilating blowers to improve the definition of details on Mars, he moralized, "It would seem almost a duty to try it." (76) Indeed, a modern analogy to Pickering's endless strivings for perfection in visual observation (whose accuracy is always compromised by the distorting blanket of earth's atmosphere) may be witnessed in the frequently irreconcilable arguments in the so-called "underground" audiophile review magazines [or, later as we would come to observe, on Usenet!]   

Finally, the Professor's arrogance led the Harvard College Observatory' new director, Harlow Shapley, to demand the return of their venerable Draper refractor to Cambridge; Pickering himself would finally be retired in 1924, though he maintained the Jamaican observatory out of his own pocket. (77) 

It seems sad to see such a youthful pioneering mind retreating into old-fogeyism, almost forgetting the leap of scientific advancement that he had engendered by espousing astrophotography. Philip N. Sadler, of the Harvard-Smithsonian Center for Astrophysics, chronicles the last great fixation of his career: a decades-long search for a trans-Neptunian planet. Now an elderly man who "did not believe the automobile was here to stay'' and who chose to ride a horse instead, (78) Pickering barraged the press with quixotic predictions of a planet beyond Neptune, starting a short time after Percival Lowell, his old friend turned nemesis, had commenced a photographic search.

Working without assistance in Jamaica, and without the benefit of the kind of simple and convenient equipment that even today's amateurs can use with relatively little effort, Pickering concentrated on a ''simple graphical process'' to utilize perturbations Uranus' orbit, following the success of Adams and Leverrier in predicting Neptune's existence in 1846. Sadler reports that Pickering chose to avoid computation by drawing a predicted perturbed sinusoidal shift in Uranus' orbit upon a glass plate, superimposing it on the actual ephemeris. By shifting around the glass, he felt he could find the ''hairpin turn'' in the planet's travels that would indicate the presence of an unknown perturbing body. 

Sadler's analysis of Pickering's work concludes that ''his successive curve fitting actually made the data worse. His 'ink upon glass' method was so subjective that it could produce virtually any curve." And by ignoring observational or computational errors, Pickering's method was fatally flawed: he was ''in effect engaged in a hopeless task." (79) Nevertheless, William Pickering published by 1930 ''seven different predictions of planets ranging in distance from 5.7 AU to 6.250 AU from the Sun and having masses of 1/20 to 20,000 times that of the Earth." (80)  Crackpot stuff, and perhaps pseudoscience: sad indeed.

The final irony is that after the trans-Neptunian planet Pluto was discovered by Tombaugh on plates taken at the Lowell Observatory in 1930, the astronomers Seth Nicholson and Nicholas Mayall went back and re-examined some search plates taken at Wilson in 1919 at the encouragement of Pickering, who had named his current prediction ''Planet O". 

In 1919 these plates yielded no trans-Neptunian planet, but when checked again, Pluto was indeed found on them, only 3.6 degrees in declination from Pickering's position. (82) With his crude empirical curve-fitting, Pickering at least in some respects had bested the sophisticated and rigorous mathematical procedure of Lowell by correctly predicting that ''Planet O" would spent part of its orbit inside that of Neptune; predictions of the photographic magnitude, longitude of the ascending node of the orbit, and inclination to the ecliptic were quite reasonably close to accepted modern values for Pluto. (83) In the end,   Pickering was philosophical. When he learned that Percival Lowell's initials PL would be used as the symbol for the new planet Pluto, the professor remarked, ''That's a good name, 'Pickering-Lowell.'' (84) After a long and productive life, the 80 year old astronomical gadfly died in 1938, opinionated and vigorous -- but mostly forgotten -- to the end.

Had the Mt. Wilson plates been scrutinized more carefully at first, professor W. H. Pickering would have been credited the successful prediction of the existence and the subsequent discovery of Pluto (at least until the critics had assessed his methods). We at least owe him recognition for the expertise that led to the photographic discovery of the Horsehead nebula! 

THE GERMAN WHO DISCOVERS NORTH AMERICA.

The world of science and engineering is replete with episodes of coincidence each time a new technology arises. Yet the streamlining process of simplifying historical perspective prefers to paint sharp contours around delicate shades of gray. We confidently confer the title of ''discoverer'' or ''developer'' upon Bell for his telephone without recalling the accomplishments of Reis or Berliner. Sir William Herschel may have provided the broad shoulders of support for all the participants in the early studies of nebulously, but it is the technical perfection of photography more than the ingenuity of any one astronomer that guaranteed the inevitable results.

Two figures are linked by historical coincidence in the running of the Horsehead derby. Contemporaries of similar interests and insights, they indeed could almost be defined by each other, their successive chapters entitled, "Wolf: The Barnard of Germany" and "Barnard, the Wolf of America".  In order of contribution the first of the pair is Dr. Maximilian Franz Joseph Cornelius Wolf (whose aristocratic name betokens a man in as high social station as Barnard was humble.)

Dr. Max Wolf, from the private collection of Prof. E. S. Holden, courtesy of the Mary Lea Shane Archives of Lick Observatory

Born on June 21, 1863 in Heidelberg, Max Wolf differed in one crucial respect from his American counterpart Edward Emerson Barnard: Wolf was not an impoverished, fatherless, self-made youth out of a rustic environment, but the well-reared son of a wealthy physician, a prominent citizen of the seat of an ancient university. But the astronomical careers of Wolf and Barnard had many parallels: as teenagers both acquired their first telescopes, and both obtained their bachelor's degrees in mathematics but one year apart. (90) Wolf discovered an important periodical comet in 1884, while by that same year Barnard had found his third such object.(91) Wolf achieved the photographic recovery of Halley's comet on September 11, 1909; Barnard made virtually the last visual observation of Halley during its then-current period on May 23, 1911. (92) Both astronomers were distinguished astrophotographers and made many discoveries by camera; each was credited by authors of differing national bias with the earliest detection of vast structure in the Milky Way, and the revelation of many of the sky's dark nebulae. (93) 

While Barnard in California was employing a six-inch aperture, short focal-length camera lens to produce widefield survey plates of the Milky Way, Wolf in Germany was employing portrait lenses of four and five-inch apertures to cover the same areas of the sky. Pictures of the instruments reveal a remarkable technical similarity: an 1898 engraving of the Heidelberg asteroid search telescope reminds one of Barnard's Lick Observatory Crocker telescope with the Willard lens in virtually all respects, save only that Wolf had mounted a second short-focus camera for producing stereo-comparator plates. (94) The photographic results betoken a good match of the astronomers' technical skills, but Barnard was the harder worker of the two, enduring long nights alone in frigid domes without the assistants that Observatory Director Wolf could employ to spell him from the drudgery of astro-guiding for many a long hour. (95) 

The wealthy American science benefactress Miss Catherine Bruce was to provide the funds for photographic telescopes in both Europe and America that would be used to great effect by Wolf and Barnard: a 16-inch aperture doublet graced the facilities of the Heidelberg University Observatory and produced many asteroid discovery plates, while the 10-inch Bruce Telescope presented to the Yerkes Observatory was employed at Williams Bay (and for one year it Mt. Wilson) by Barnard, producing his finest photographs of the Milky Way and dark nebulae. (96) 

Gerrit Verschuur in his book "Interstellar Matters" claims that ''neither man referred to the other's work, perhaps not surprising considering that communication was very slow at best" (97) but in truth -- as the present author discovered from copious evidence in the Lick archives --  Barnard graciously extends the credit for the first photograph of the great nebula north of Alpha Cygni to Wolf, writing in a 1903 article that it "was first photographed by Dr. Max Wolf some twelve years ago and has been called by him the 'American Nebula' from its striking resemblance to North America as shown on maps and globes." In a footnote, Barnard continues, "The 'North America Nebula' would perhaps be more definite, for it is North America to which Dr. Wolf intends the compliment." (93) Wolf, turn, confirms "the great nebula discovered by Mr. Barnard in the cluster G. C. 1420 in Monoceros" in his  account of various nebular photographs taken up to the year 1891. (99) 

Both Wolf and Barnard were frequent contributors to the German publication Astronomische Nachrichten, a leading professional journal found in the libraries of all the great observatories, so despite Verschuur's assertion, the major discoveries of these two skilled observers should have been well known to each other and to the entire astronomical world, at least within a year or two of the appearance of their articles.  And Barnard, humble man with merely a bachelor's degree in mathematics, was familiar with the social protocols of 19th century science, and an astute observer of same -- at least until his notorious contest of wills with his boss at Mt. Hamilton, Professor Holden! Barnard would, at that time, have been the last person in professional astronomy to willfully dismiss or ignore a much more famous colleague.

In 1903, the same year of Barnard's previously quoted comments about Wolf, the German concludes from studies of deep exposures of the constellations Cygnus and Orion that areas of the richest extended nebulosity are accompanied by "regions nearly void of faint stars" (100), echoing the remarks of W. H. Pickering in his 1895 Harvard College Observatory paper. (101) The photographs taken in Cambridge led the Harvard astronomer to report the possible existence of light-attenuating non-luminous gases, but there Pickering dropped the issue. Wolf, like Barnard, was deeply impressed by the voids or 'heavenly holes' and asserts that ''all extended nebulae are situated in the interior of regions containing only a very small number of faint stars...My assistant, Mr. Kopff, has published an exact enumeration of the stars about these objects, from which it is proved that nearly all faint stars have disappeared from the immediate surroundings of these nebulae, though they are ten times more numerous both in the nebulae themselves and far outside." (102) 

While it is not strictly true as Wolf states that "all extended nebulae" are surrounded by areas lacking the dimmer stars, he is on the right track when questioning, "Is there a dark mass following the path of the nebula absorbing the light of the fainter stars?" (103) A dozen years earlier, Dr. Wolf's interpretation of dark markings in the sky is more conventional, following along Herschel's lines of reasoning about "holes". In Volume 127 of the Astronomische Nachrichten, covering submissions from 1891, Wolf publishes his report "On the Great Nebula around Zeta Orionis'', imparting news of his discovery that 

  "The star Zeta Orionis is surrounded by an extraordinary expansive nebular mass, photographed in six different exposures taken with three different photographic objectives, the first preserving the image on December 12, 1890."

The region to be later cataloged by Dreyer as IC 434 is described by Wolf as ''broken by an oval bay." (Waldee's translations) (104) Thus, Dr. Wolf -- like W. Pickering, Dr. Isaac Roberts, Heber Curtis, and most other early Horsehead commentators -- considers the dark region to be a feature of the nebular streak IC 434 and not a superimposed opaque body. The present author is sad to state that he searched Wolf's articles in vain for description of a ''pferdkopf'' (horsehead).

In the Journal of the British Astronomical Association, Wolf submits from Heidelberg on February 17, 1891 a "Note on a Nebula surrounding Zeta Orionis discovered by Photography", summarizing his own independent conclusions on the proper techniques for capturing extended nebulously, as opposed to the point sources of starlight.

   "A year ago I photographed the Pleiades with a 2-1/2 inches aplanatic lens by Steinheil, and I was surprised to obtain, with an exposure of one hour, all the nebulae which the MM. Henry obtained only with an exposure of several hours, using a large telescope of 13 inches aperture.

  "If considered more carefully, this result was to be expected, as an example will show. Let us compare the 20 inches reflector of Mr. Roberts, having a focus of 100 inches, with an ordinary portrait lens of 4 inches aperture and 12 inches focus.

  "In photographing the fixed stars the intensity of the image depends only on the area of the lens used. In this respect the Roberts telescope, ceteris paribus, would be 25 times superior to the portrait lens...But it is a quite different thing with objects which show a finite area, as nebulae, comets, &c...Therefore it is not only cheaper to use ordinary photographic lenses, but they are also better suited for finding new nebulae.

  "I have used such lenses mounted on my 6.4 inches refractor with much success during the last few months."

After comparing his photographic work to visual discoveries of Barnard and Herschel, Wolf arrives at the new subject revealed on his latest plates:

  "But the image of the nebula surrounding Zeta Orionis, a reproduction of which I have sent to the Association, is quite a marvelous object. The part of the nebula east of Zeta is G. C. 1227, drawn with much detail by Lord Rosse...The extremely large and interesting nebula S. W. of Zeta, also the nebulous ground around Zeta and the nebulous star north of Zeta, do not appear to have been seen before.

 

   "The reproduction you received is an enlargement with an unimportant 'retouch' from a plate which took on January 2nd, 1891, from 7h 0 til 12h 30 with a Kranz Euryscope of 5-1/4 inches aperture, using the 6.4 inches equatorial as a guiding telescope; and was relieved my work by the Messrs. Rosenplaenter, Staus, and Zangemeister.

 

   "Besides this long exposed plate I obtained also the same nebula...with a Voigtlaender Euryscope of 4 inches...(and) with a Millet portrait lens of 4 inches, with exposures of from 1 to 3 hours. (Plates from Messrs. Lumiere of Lyons.)

 

   "I have still to add that I cover the back of the photo with a mixture of linseed oil and pine-soot to avoid the rings around the brighter stars, according to the method I published some years ago. Thus, I never obtain disturbing rings around the bright stars, even by the longest exposures." (105) 

As mentioned in the account of Harvard's publication of the photographic discovery of the Horsehead nebula, the British journal's editor, E. Walter Maunder, adds a lengthy footnote clarifying and correcting Wolf's article.

    "Miss Clerk has kindly drawn our attention to a paper by Mr. W. H. Pickering...in which he describes the discovery of a number of new nebulae by means of photography. On p. 116 there is the following note upon 'Nebula No. 21,' which is evidently that shown on Dr. Wolf's photograph."

The note subsequently quoted is the 1890 Harvard Annal's description of the nebula south of Zeta Orionis that contains the "semicircular indentation" we now call the Horsehead.

Maunder updates the older G. C. numbers employed by Wolf to the equivalent New General Catalog numbers of Dreyer for the objects photographed near Zeta Orionis, and concludes: 

  "It appears then, that Dr. Wolf's photographs do not actually show any new objects. But they correspond most satisfactorily with the results obtained by a much larger instrument." (108);

The photograph by Max Wolf of the ''Nebula surrounding Zeta Orionis'' published on p. 297 of the 1891 British Astronomical Association Journal clearly shows the Horsehead, but suffers from the restricted gray scale of the primitive printing techniques of the era. The ''unimportant 'retouch'' that was probably required to clearly depict the sharp notch of dark nebulosity does give the photograph an artificial quality in contrast to the accuracy of the ''collotype'' prints of Barnard's Milky Way photos, but one can imagine that the original plate was a very good one. Star images are perfectly round and clean, showing excellent focusing and guiding; the absence of the distracting halation rings indicates an improvement over Pickering's achievements.

Some reprocessing to stretch contrast was done by the photo lab at Lick Observatory, but -- unfortunately -- that copy has been lost by Kalmbach Publishing. Thus, the picture was further degraded by our surviving photocopy, and required extensive digital image processing to improve the distinction; though IC-434 and the Horsehead region are recognizable, the result is unnatural compared to what one would expect from Wolf's original negative.

Despite the limitations of the reproduction, this 1891 photograph portrays the Horsehead region much more dramatically than in the very small and low-fidelity image on p. 111 of the 1895 Harvard College Observatory Annal.

In addition to his work on the nebulae, Dr. Max Wolf was distinguished for many pioneering celestial applications of photography: multitudes of faint asteroids and numerous variable stars, plus comets and novae, yielded to Wolf's skilled method of search with the optical stereo-comparator, invented for another purpose but first employed for astronomy by the German professor in 1901.

Two final similarities between Wolf and Barnard must be mentioned. Each was associated with one observatory for the bulk of his career, the American at Yerkes for nearly a quarter of a century, and the German in Heidelberg for a patient and productive thirty-five years. In a concluding biographical note that could be equally and uncannily applied to Edward Barnard, Wolf's friend Hector Macpherson wrote of the great German astronomer's career, 

  "Wolf's activity did not appreciably diminish with the passage of the years. Despite failing health, he retained his [activities] right up to his death...The news of his passing occasioned deep sorrow all over the scientific world. One of the kindest, humblest, and most lovable of men, he had many friends as well as admirers.'' (107) 

So we can add to his many achievements that when the 70- year-old Dr. Max Wolf died on October 3, 1932, not the least of his feats had been the 1891 publication of the first really satisfactory large-scale photograph of the Horsehead nebula.

THE WILLARD AND THE WORKAHOLIC

Lick Observatory Main Building Entrance on Mount Hamilton,
near San Jose, California: photographed by author, 1989

The sight of the snowy crest of Mount Hamilton is an incongruity during shirt-sleeve weather in the Santa Clara valley. Winter seldom brings more than frosted tips to San Jose lawns, but January and February chills endow Lick Observatory at its 4200-foot elevation with the full complement of seasons denied to the valley below. The narrow, winding Mt. Hamilton road (with more than 350 turns and switch-backs) discourages all but the most sporting of winter visitors. Like their turn-of-the-century ancestors, the astronomers and staff at the observatory may occasionally be snowed in at the top, but the isolation is short-lived thanks to the bustle of road and utility service crews. Even when the drifts pile four feet high, the incessant babble of radio and TV signals -- almost too many of them, strong and clear at such an altitude! -- easily staves off the sense of withdrawal that made winter mountain life a century ago resemble a term of solitary confinement.

Our visits to the observatory are always in spring and summer, when the crisp, clear, and tranquil air acts as a tonic to lungs accustomed to Silicon Valley smog. Then the author and his wife (musician and teacher Regina Roper) meet with the UC/Lick history docent W. Shiloh Unruh to prepare for the annual ''Music of the Spheres'' fundraising classical music concert at the Observatory.

Since his childhood, Shiloh has been drawn to the hill as if by a magnet; he has lodged the century-old dry dust and plaster under his nails, has crawled behind walls and into abandoned nooks in the old main building, and has sifted through ashes for bits of old pottery and glassware. Seduced by the siren-call of history, Shiloh has scoured libraries for photographs of stern-faced men in celluloid collars and solemn women in florid hats; he has trekked the journey first taken by Lick astronomers back in 1889 to photograph a solar eclipse from the tiny California village of Cloverdale. [Note: Mr. Unruh's association with the Observatory came to a close around the year 2000.]

Shiloh conducts walking tours of the site Lick mansion near downtown San Jose, and is saddened that this once quiet and fertile orchard property has had its ground and its sky polluted by 20th-century progress. He has even searched for the factory of old Charles Feil in Paris, the glassworks where the blank for the mighty 36-inch refractor was poured in 1885. (109) 

James Lick, the homespun millionaire who endowed the Observatory, would appreciate one of Shiloh's hobbies: making fortepianos and harpsichords. The skilled carpenter and furniture-maker Lick began acquiring his fortune by providing pianos for the music loving citizens of Buenos Aires, Valparaiso, and Lima (109) 

In early September we gather again to present our concerts in the great telescope's dome, a dark cathedral-like confinement which opens up at night to admit a slit of starry sky into the enormous lens of the second-largest operating refractor in the whole world. For the short span of a decade, this marvel of 19th century's technology was the biggest such instrument in existence, and its power and precision could seek out tiny, obscure objects like the fifth moon of Jupiter, discovered by Edward Barnard in 1892, a scant two weeks after being permitted a regular observing schedule with the great telescope. (110) Yet such is the nature of long-focus refractors that this mighty Warner & Swasey machine needn't have existed in order for the Horsehead to be revealed. For it was not the huge Alvan Clark 36-inch objective, but an obsolete cast-off lens of only 6 inches' diameter that in 1894 first photographed the dark nebula at the Lick Observatory.

A noble machine, the Warner & Swasey-built Lick Observatory 36-inch Refractor, with objective lens by Alvan Clark & Sons. Photographed in 1989 by the author.

The unaccustomed crunch of winter snow under our feet reminds us that as amateurs, we are now present on the top of Mount Hamilton on a cold February afternoon by the permission and courtesy of the professionals who protect this outpost. We are led where visitors seldom go, into a private sanctum to inspect the preserved objects of this priestcraft with one of its senior practitioners.

Eugene Harland has been at Lick Observatory for three decades, coaxing images from all the instruments on the mountain. He has seen the photographic plate supplanted by the electrical components of the CCD, and has observed for the long span of years it has required to photograph a ''movie'' of the evolution of fascinating nebular Herbig-Haro objects, protostars emerging from the depths of dark globues of interstellar matter. (111) Gene has even discovered his own comet (an accidental by-product of another project) that turned out to have an estimated 800,000 year period. One wonders if earthlings will care to observe its return, and how they will differ from our current species! 

Our small party of Horsehead researchers enters the Lick Observatory plate vault under Gene's watchful supervision. My companions are Richard Page (through whose own homemade 6- inch reflector I first observed some [44] years ago) and the father-and-son astrophotography team of Ron and Ryan Wood. 

The three of them are avid and skilled amateurs: Rich has built a massive and excellent 14-inch aperture German equatorial; Ron has figured his own superb 8-inch mirror, and prints his own and his son Ryan's astrophotos. An atypical 15 year old, Ryan patiently endures guiding three-hour exposures to secure crisp deep-sky shots of clusters, galaxies, and nebulae. Like Shiloh, I have caught and can't shake off the history virus, and am perfectly content to follow the same pathways that the professionals cleared a century ago.

An ancient safe that could have adorned a Northern California 'forty-niner' assay office, and ornate wooden cabinetry that would have impressed master carpenter James Lick, fill the first of two elegant rooms that contain the original photographic plates that have slowly accumulated for a hundred years. These glass relics are instructive to the late-20th century technological chauvinist, for they demonstrate that the art and science of astronomy and photography were mature and profitable during the first decade of the Observatory's operation: the information contained on these old plates can long benefit researchers who study novae, proper motions, and stellar evolution by accurately verifying the state of the heavens many long years ago.

In the inner rooms, arranged as a lengthy corridor broken by two huge doors that help maintain a constant temperature and freedom from moisture, are the oldest of the plates and observing records. Ceilings are at least ten feet high, and one must climb a ladder to reach all of the shelves, which are enclosed in fine-crafted glass cabinets to keep out the last speck of mountaintop dust. The right-hand wing contains the observering books of the early generations of astronomers, recording their impressions as they worked at the telescopes, spectroscopes, and cameras; or their later reductions of data, laboriously calculated without the benefit of modern electronic computers. 

The hundreds of fancy bound volumes of lined paper, neatly labelled on their spines with the initials of S. W. Burnham, E. E. Barnard, E. S. Holden, and all the rest, remind one of the library of a Victorian law office, but when we open them we are confronted not with torts and arguments, but a bewildering array of handwritten scribbles, mostly in pencil, of fragmentary comments, Greek letters, tables of figures, and planetary or lunar drawings.

Burnham's penmanship -- especially his elegant signature -- is regular, readable, and beautiful, while that of Lick's first Director, Dr. Holden, is bold and forceful. But we resist the temptation to while away time and soak in impressions, being here to examine the notations of Edward Barnard and specifically to see any comments on his Milky Way photography can shed light on his early knowledge of the Horsehead nebula. Barnard spent but two months' attendance in school as a child, (112) and his scrawl is sometimes clumsy and crude: it will be necessary for two or three of us to examine the markings and discuss what they must mean.

Gene knows that with the enormity of the material present, a blanket search will be time-consuming and fruitless, so he insists that we start with the exact dates that Barnard photographed the constellation of Orion. I have brought copies of Barnard's famous Milky Way photos in the 1913 Lick Observatory publication, so we should know the precise date that the first Horsehead picture was obtained on the mountain, but the heavy books are still in my car, a quarter-mile away down a long, icy, winding road up to the main building. Ron Wood starts the slow. slippery journey on foot since Gene is loathe to permit me to start rifling through the notebooks. While waiting for Ron, I examine the plate room with Gene Harland.

In a duplicate set of glass cabinets are the oldest of the negatives taken with the Lick refractors. I glance down near the floor at a collection of enormous survey plates in a cubby-hole labelled "Vulcan, 1905." Inside ancient manila envelopes, much thicker than today's paper, are fragile photographs taken from a search for the chimaerical intra- Mercurial planet that was supposedly seen by an amateur, the French pysician Lescarbault, in 1859.

Vulcan, and for over 50 years afterwards it was hunted in vain. At each solar eclipse, when the best hopes existed for capture, a glimpse or photograph of the elusive disk without the intense obscuring glow of scattered sunlight, Vulcan was sought, fueled by claims of purported sightings and the press-agentry of such newspaper popularizers as Camille Flammarion, who also eagerly promoted the existence of the Martian canals.

In the first years of the 20th century concerted efforts were made by Mt. Hamilton astronomers to verify Vulcan's existence, but Lick Observatory's second director, W. W. Campbell, concluded after a 1908 eclipse expedition that further search was pointless, and soon the supposed body was generally declared nonexistent. (113) 

Jestingly I asked Gene to point out Vulcan on the old plates, and for a moment I believe he thought I was serious, for he began patiently to explain that it didn't exist (in 30 years on the mountain, one has had to dispel politely a lot of the public's quaint notions of astronomy.)

While we waited for Ron to return with the notebook, Gene showed us what may have been the Observatory's second photograph of the Horsehead contained in a magnificent 1911 plate taken by the Willard lens and the Crocker telescope.

It is impossible to exaggerate the delicacy of the images on an original frail astrophotographic glass negative. Unlike low fidelity and contrasty half-tone magazine reproductions or grainy drugstore sky prints that many amateurs are used to examining, a genuine glass stellar negative posesses an airy pointillism of faint markings and microscopic dots. On this exposure, the tracery of 1C-434 was such a fine and shadowy powdering: that one could almost imagine the slow accumulation of each fugitive photon on the old, slow emulsion. Yet the Horsehead region was so starkly transparent against the weak dusting of nebulosity that this sharp ''dead spot'' appeared as though it had been scraped clean from the dim remnants of skyglow. The camera's wide field had captured almost the entire constellation of Orion, so that one had to hold the plate up to a strong light to see in the region south of Zeta Orionis the tiny 2-millimeter Horsehead depiction.

After we obtained the date of the original Barnard plate of the constellation, Ron, Ryan, and Rich scoured the appropriate notebooks for any interesting comments. Sure enough, on the night of October 3, 1894, Edward Barnard scrawled his references to the photography of Orion, but with no illuminations in later pages about any discoveries of objects upon the plates. We can be certain, however, that the diligent Barnard spent long hours with a magnifier plotting and measuring each of his pictures, and was well aware of the ''curious nebular ribbon'' containing the Horsehead by the time of the publication of his 1903 paper on "Diffused Nebulosities in the Heavens." (114) In Barnard's 1894 Willard photograph, as reproduced in the Lick Publication of his Milky Way and comet photographs with the Willard lens, the Horsehead is fainter than the image on the Pickering discovery plate, and no wonder: Gene showed us a reference card on the Willard lens, recording that Barnard used a diaphragm between the front and back elements of the doublet, cutting the aperture down to less than 4 inches! (115) This tiny area of class, employed in the shadow of the great Clark 36-inch refractor, provided Edward Emerson Barnard with the raw material for the pondering of the next three decades of his life.

Edward Emerson Barnard

Edward Barnard in the 1890s, courtesy of the Mary Lea Shane Archives of the Lick Observatory

Reuben Barnard died before his son Edward Emerson was born on December 18, 1857, forcing the youngster's mother to eke out a hard existence supporting herself and two sons by taking on various jobs, including has been written, classic American modeling wax flowers. The trauma of the Civil War deeply affected the boy, who could never forget the clash of arms at the Battle of Nashville. Edward was racked by malnutrition and cholera, and for the rest of his life carried a scar on his chin from a sore that his delicate constitution couldn't heal. inspirations came after lengthy and careful physical observations. (116) 

Seventeen long years working for a Nashville photographer, beginning as a mere boy to help operate a huge enlarging camera that had to track the sun, prepared E. E. B. for a career that required calm, centered patience. 

"About this time," writes Barnard's friend S. W. Burnham, ''a traveling show-man with a small glass for street exhibition turned up in Nashville, and young Barnard was a steady patron whenever nickels were sufficiently plenty to warrant such a dissipation.'' (117) Interestingly enough, such a peripatetic astronomer had visited James Lick at his mansion in 1860, staying for a few days to demonstrate views of the heavens to the fascinated old man, who was not usually wont to display much hospitality. (118) A rather similar experience had occurred to the master optician John A. Brashear when as a 9-year-old lad 1849 he had paid a small fee to one ''Squire Wampler'' of McKeesport, Pennsylvania, for a view of Saturn and the Moon. (119) The lives of these three men were to be subtly intertwined in the eventual production of the famous Milky Way plates that had brought our present little group of amateur researchers to Mount Hamilton.

Edward's subsequent self-study of astronomy and efforts to improve his back-woods demeanor are well known.  Burnham recalled that ''Handicapped by the sorest distress and poverty from the first he has fought the battle of life alone and is in the supremest sense of the word a self-made man." (120)     

Conscious of his humble status but compelled by interests and ambition, Barnard sought a brief audience with the esteemed theoretical astronomer Simon Newcomb, who gruffly discouraged the unschooled youth from expecting any success as a professional scientist, dropping but a few scant words of encouragement for the boy to be a seeker of comets, an activity that required little mathematical knowledge.

Barnard departed in tears, but would soon make a name for himself as the prolific discoverer of ten comets by the time he would receive an appointment to join the staff of Lick Observatory in 1887. (121) 

Like great creative compulsives from Beethoven to Bonaparte, Barnard obsessively drove himself towards achievement in prodigious outpourings of energy, but he had the inner-directed stability, lacking in dilettantes and dabblers, to focus his efforts and produce significant results. Soon the grip of comek-seeking fever overcame him, and he even dreamed one night of a sky full of multitudes of the fuzzy, streaming bodies; upon awaking, Barnard discovered that the bright comet of 1802 had broken into 10 or 15 fragments, which he duly swept up in his telescope and reported by wire. But his telegram failed to reach its destination, and thus he lost the credit for this particular find (122). But the money earned from his other awards for cometary pursuits paid not only for his abode, called ''Comet House", but also for Barnard's tenderly solicitous care for his frail invalid mother, whose mind had slowly dimmed from the struggles she had endured. (123) Barnard was greatly aided by his faithful wife, born Rhoda Calvert in England, whose brother had been Edward's colleague at the photography studio. Mary Cavert, Barnard's niece, was later to assist the astronomer as his secretary, compiling and cataloging over 900 articles and papers;  his published works eventually numbered nearly a thousand (124).

When Barnard arrived at Lick Observatory in the early summer of 1888, he had accomplished much already, not the least of which was his diligence in earning against all odds a Bachelor's Degree in Mathematics from Vanderbilt University while working as an undergraduate astronomy instructor. But one imagines that in comparison to the scholarly James Keeler and John Schaeberle, Barnard's colleagues at the new observatory, the young self-taught zealot may have been regarded by Lick Director, Professor Edward S. Holden, with some faint condescension. Barnard may have been slightly tainted because most of his discoveries had been made, after all, while he was still 'merely an amateur.'

Holden, whose rather bug-eyed intensity glowers from every portrait, was an astronomical blueblood and an accomplished academic. It is clear that Barnard had somewhat cringingly courted the new Director, for he wrote on August both, 20th, 1887, "...I had made up my mind this summer to cease Comet Seeking and to get into a higher class of work...I hope you will aid me in this determination. My associations here (at Vanderbilt) have been the pleasantest, and I leave only because of the superior advantages that the Lick Observatory will afford me. Another strong inducement is (for I have always had the highest admiration for you personally) that I shall be immediately under your charge, and shall receive the benefits of your training.'' (125) 

Knowing of the conflict he was to suffer, one is saddened  to scan the original letter of Barnard as preserved in the Lick Observatory's Mary Lea Shane archives: chafing with frustrations he nonetheless discovered Jupiter's fifth moon; created the Milky Way photographs (revealing of many of the sky's   dark nebulae); discovered the first comet found by photography; made innumerable observations of newly-seen double stars, asteroids, and nebulae (many now known to be galaxies); carefully measured positions during occulations and eclipses; and left superb drawings of planets and the Moon. (126) 

Despite the opportunities provided for such accomplishments, Barnard would soon lose his awe and regard for the authoritarian Holden, accusing him of "taking special delight in goading me", (127) diverting precious energy from observing into dueling with Barnard's implacable enemy "The Devil", as the Director came to be characterized by mutinous embers of his mountaintop staff. (128) 

Holden's imperious attitude, and the consequent reactions of his skilled and sensitive underlings, can be judged from as little as two brief documents from the Shane archives. Tempers soon flared at the Observatory, with the Director and his disgruntled astronomers communicating officially by passing memos back and forth, designed to present for the scrutiny of the University of California regents their respective positions in each altercation, disagreements sometimes petty but often deep and divisive.

The first of these two examples reads: 

''September 18, 1890

 Professor Edward S. Holden

         Dear Sir

     We insist at all times that whatever difference of opinion there may be between our views upon  scientific subjects -- your conduct, both oral and written communications, shall be gentlemanly.

Among other things in your communications of yesterday the use of the word sneer is unworthy of your official position.

            S. W. Burnham

            M. Schaeberle''

Attached is the response of the Director, penned neatly in the bold broad hand that reflected his strong military bearing: 

''Sept. 16, 1890 

Not answered. Filed with the suggestion that the writers have evidently forgotten the expressions employed by them in speaking to me of my letter to Mr. Crocker relating to the missing vouchers to their eclipse accounts.

E. S. H.'' (129) 

A graphologist would take note of Holden's dramatic detached flourish on the final s of the word ''vouchers", perhaps betraying his smug satisfaction at having found an alleged example with which to discredit his critics. Obviously all parties to any of the disputes were going to insist that each argument would have two clearly-drawn sides.

With due credit to Director Holden, it must have been wearying to arrive early at his desk in the morning, fatigued from a night spent observing until 12 o'clock in the frigid dome of the great refractor, and after stoking the reluctant fire in the smoky hearth -- great winds blowing through the chilly building, blowing about any hapless missive -- to sit down at last at his desk, only to confront on the very top of a stack of documents an angry submission from a fuming Barnard, such as the following memo of September 2, 1895:   

''To Professor Holden.

My sleep is constantly being broken in the mornings by the observatory wagon going back and forth by our house to the Crossley telescope. To one working all night this loss of sleep is distressing. This occurred again this morning, after I had got but little sleep, by the heavy team coming over to get a lot of packing cases that have lain there for a month or so. I respectfully request that this unnecessary nuisance be stopped and when possible such work be done the afternoon. Respectfully, 

E. E. Barnard'' (130)   

A subtle inference must be noted: Holden had arbitrarily denied Barnard official access to the world's largest telescope, though the Director reserved it for himself on two nights of each week. A clumsy and desultory observer, Holden produced photographs that were too often blurry and useless. (131) Tiring by midnight or so, the Director would frequently close the dome and trudge off to his dwelling, leaving the great, indispensible scientific instrument quite idle. 

Barnard the brilliant observer and voracious comet-discoverer was not even permitted to use it after Holden retired for the evening, as presumably this would have been too embarrassing for the Director. 

Note that Barnard reminds Holden pointedly, ''To one working all night", [Waldee's emphasis] "this loss of sleep is distressing." Holden's justification, printed on another occasion in an article written for the Journal of the Astronomical Society if the Pacific that the professor himself edited, explained that, "Before the least scientific work can be done, life (on Mount Hamilton) must somehow be organized...The energy that is left over is available for astronomical work.'' (132) 

The Director's high-handed behavior eventually caught up with him, and became something of a scandal, noted in the newspapers: the regents could no longer ignore it nor discount the disagreements at the Observatory as being merely the prattlings of neurasthenics suffering from isolated mountain-fever.  As befitting his sense of dignity, Holden's departure from Lick Observatory was not accompanied by Shakespearean dramaturgy. With public opinion heavily on the side of the astronomers, he quietly packed and left prior to his official resignation. One job after another eluded him, so Holden supported himself by writing torrents of articles,. not all on astronomical subjects. Dr. Donald Osterbrock notes in his monograph ''The Rise and Fall of Edward S. Holden'', that the former esteemed Lick Observatory director and scientist was not above churning out a light essay on etiquette (''What is a gentleman? A Lady?") under the pseudonym Adam Singleton for the old Cosmopolitan Magazine. (133)

A lasting accomplishment at the end of his career was a return to West Point for the position of librarian. There the bibliophile Holden could work in an atmosphere pervaded by ''an infusion of some military order'' (134) that he had not managed to sustain among the rugged individualists atop Mount Hamilton.

How remarkable it is that today, nearly a century after the struggle between the established and respected Edward S. Holden and the upstart but sincerely dedicated Edward Emerson Barnard (called neurotic by Osterbrock based on his extensive  study of the myriad of self-pitying letters in the Shane archives), (135) the tables are firmly and irrevocably turned. A few hoary remnants of Holden's personal works can be unearthed, such as a pitifully slim and sketchy volume on the life of William Herschel, preserved in the University of California Science Library in Santa Cruz, or in his literate but scientifically- thin dissertation on historical visual observations of the Orion nebula.  Whereas Barnard's accomplishments caused him to be venerated -- almost idolized -- by his former colleagues, judging from the threnodies published just after the great observer's death on February 6, 1923. (136)   Holden's true legacy must be measured indirectly, from the establishment of a progressive policy of photography and astrophysical research at Lick Observatory, to the acquisition of the Crossley 36-inch "fast" reflector, and the creation of the famous Lick astronomical library.

Anyone who has held a sometimes thankless executive position cannot despise Holden for failing to secure a perfect balance between establishing the needed mountaintop discipline, and nurturing the occasionally conflicting needs of the University administration, highly-strung astronomers, and the public benefactors of Lick Observatory. "We are all more or less like the horses of these mountains! We get 'loco' as they say," wrote Holden to a U. C. regent in 1892. (137) But despite a sad demise, Edward Singleton Holden was far from being merely the Captain Queeg of the ship afloat the starry realms of Mount Hamilton!

THE QUIET, STEADY WORK OF A PATIENT GENIUS

Now the stage has been set for the work of Edward Emerson Barnard in the tiny dome near the old water tank on one of the hilltops at Lick Observatory. A superb old black-and-white photograph of the era shows the master's gentle touch applied to the Crocker telescope controls, his arms outstretched tirelessly to operate the right ascension and declination guiding adjustments during long exposures of the slow dry plates affixed to the rear of the Willard camera; one might almost imagine hearing the echo of the slow, steady ticking of the clock drive inside the dingy tin dome. Barnard will remain standing in this uncomfortable position for up to 5 or 6 hours at a stretch, his eye glued to the ocular of the guiding telescope, as he precisely regulates the tracking clock which follows the relentless sidereal motion of the heavens. His eye never leaves the defocused image of a bright star, the soft flickering blob of light behind the fine iron crosswires of the guiding eyepiece. (138) 

From time to time he will have to wind the clockworks without spoiling the plate, and to push the dome around to keep the clear sky always in front of the optics. No assistant helps him; no heater may be employed lest its radiant waves spoil the sharpness of the images; no electrical appliances provide the torque to spell the labor of his muscles; and no radio plays softly to entertain him with soothing music during the long hours. If the camera slews across a great arc of sky, he may have to fiddle carefully with the dangling counterweights of surplus iron to compensate for changing atmospheric refraction, maintaining pinpoint-crisp stellar images on the negatives.

Edward Barnard, obscured by controls of the Crocker Telescope with the Willard Lens, Mt. Hamilton, courtesy of the Mary Lea Shane Archives of Lick Observatory

Wind rolls up the sides of the hill, whistles and howls through the rattling dome and building, its chill creeping into the observer's bones. Distant coyotes cry out in the night, bringing no frisson of fear for the sky is far from being frighteningly black: photons from the innumerable stars of the Milky Way stream through the slit, bathing the inside of the sanctuary with dim grey starlight, an effete eery glow like the dregs of energy strained from the sun until almost nothing is left to shine. This may be work for a poet, but not for one who is faint of heart.

An astronomer, like no ordinary woman or man, measures time in decades, centuries, millennia, eons. Barnard will be patient: the perfect images on his precious plates, recording plangent waves of luminosity, the dense knots, chains, and swirling maelstra of clusters and asterisms, rifts and sudden black depths, fleecy stellar cumuli, and the mysterious elliptical nebular smudges, will become known to his colleagues and the public only when just the right conditions prevail. It will be necessary to secure official approval, to acquire considerable funds to cover posts, and to experiment almost endlessly with printing techniques to satisfy the perfectionist.

In all, more than two decades must elapse after the Milky Way impressed its light on the earliest of the plates, for the now-famous but unseen pictures to be published. Imagine the different pace of life then, versus today: would such elderly research still be considered fresh and exciting some twenty years after its completion? Yet Barnard's photographs revealed then -- even to professionals -- a richly detailed architecture of the sky not perceived visually through the old-fashioned long refractors.

By the time that Volume 11 of the Publications of the Lick Observatory came to be printed in 1913, E. E. Barnard had mellowed. Now a distinguished professor of astronomy at Yerkes Observatory, required to teach no students but merely to observe, photograph, and ponder (139), and treated with compassionate warmth by its founder George Ellery Hale, Director Edwin Frost, and all his contemporaries, Barnard was free from some of the insecurities that had made his earlier days so painful; yet though he had won the Lalande Gold Medal of the French Academy of Sciences for discovering Jupiter V (140), he was only too aware of his own and fellow astronomers' limitations of knowledge when confronted with the mysteries of the Milky Way.

Barnard's intellectual honesty compelled him to confess in the pages of the Milky Way publication that he had erred in improperly fixing the images on the earliest plates, in dramatic contrast to the supremely self-content Holden. (141) Perhaps his inner demon kept Barnard a sweet and decent man, in the words of Yerkes colleague Philip Fox, 

  ''marked by a great simplicity of character, great modesty, perfect unselfishness and self-abnegation; a most kindly and genial spirit. most tender-hearted, making any distress of his friends his own distress, of such character as to make him genuinely loved by all who knew him; his home was one of cordial hospitality.'' (142) 

Barnard could be a hearty soul, often singing the darkroom in a not-too-gifted voice. (143) His sense of humor can sometimes be evident even in the pages of a scientific publication, judging from this amusing account of one obscure aspect of making the Milky Way photographs: 

  ''To judge from the almost entire absence of electrical storms on Mount Hamilton, one would get the impression that very little electricity was present in any form. While guiding, in making these photographs with the Willard lens, however, the writer frequently met with a singular experience which, while may not be a new one, was at least an unknown feature to me at the time. Perhaps I may be permitted to describe it in connection with the present work. 

"On chilly or cold nights I wore an Esquimaux [sic] coat made of reindeer skin, and heavy rubber overshoes. Frequently, on bringing the eye to the telescope on such nights a spark would discharge with a slight shock between the eye and the eyepiece. This was extremely annoying, and finally became so disagreeable that it was found convenient frequently to touch the metal instrument, which would produce a discharge from the finger instead of from the eye. The probable explanation of this phenomenon is that it was due to the fur coat and the insulation of the rubber overshoes, the body becoming electrically charged like a Leyden jar. The approach of the eye to the eyepiece would discharge this electricity into the telescope from the eye. This phenomenon, under similar circumstances, sometimes occurred in observing with the 36-inch refractor. Neither telescope, at that time, had any electrical appliances.

"On one occasion, when going to bed in the early morning, the conditions were such that rubbing the hands over the sheets produced a perfect shower of sparks, apparently threatening to set the sheets on fire." (144) 

No doubt this account speaks much of Rhoda Barnard's patience, and should be of some solace to many an astronomy 'widow'!   

In the early Lick period, full of his mission but all too aware of his humble beginnings, the ambitious astronomer fussed over a statement published by Holden that ''Mr. Barnard had made some experiments (in photographing the Milky Way)...in 1889, with the promise of most satisfactory results.'' At the time, Barnard had replied with fervent protestations that his work was emphatically not experimental, and felt it was thus being diminished by an unappreciative and spiteful Holden. (145) 

Yet by 1913, the matured Barnard could himself write in the Lick Publication Volume 11 that, ''The results of some experiments which I made (with the 6-inch Willard lens)...in photographing the Milky Way were very beautiful and intensely interesting. When the importance of the lens for such astronomical work became apparent, Professor Holden placed it in the hands of Brashear, who refigured it and greatly improved the definition of the star images.'' (148) 

Barnard earlier in the same work pays his homage to the previously-reviled ''Devil," writing: "I am indebted to professor E. S. Holden, former Director of the Lick Observatory, for placing the Crocker Telescope at my disposal for the work of securing these photographs.'' (147) The conventions of good manners and the protocols of professionalism may conceal Barnard's true feelings. but as he was by all accounts a benevolent man, it might be best to suppose that he was at last charitable to his old adversary.

The scene crossfades back again to the late 20th century...

Gene Harland led Rich, Ron, Ryan, and me over the short but nonetheless perilous and icy path back to the high-vaulted main building of Lick Observatory and, past the old post office boxes of the mountain dwellers, down a hallway in a remodeled section that was reminiscent of modern school corridors, to another off-limits repository. Through a room neatly stacked floor-to-ceiling with cardboard fileboxes of Observatory paperwork, we stepped across another time warp threshold to a treasury packed with the silvery coinage of collected starlight. Row upon row of metal shelves on one side contained multitudes of copies of Lick Observatory publications, here a paper on spectral analysis of one stellar body or another by means of the Mills Spectrograph, there a volume of the nebular photographs made at the turn of the 20th century with the 36-inch Crossley reflector. On the other side of this long vault of astronomical history was another antique cabinet bearing a proud woodworker's art. Behind glass windows reposed slightly tarnished and well-used micrometers. ancient electric lamps, and enormous eyepieces with massive fixtures and attachments unfamiliar to modern amateur astronomers, the precisely-crafted instruments of the old astronomy of a slower if not always more cordial age.

Gene Harland stooped laboriously to retrieve a heavy, unwieldy object. He and Ron stepped back and held up the Willard lens for the rest of us to acknowledge.

Willard Lens in 1989: left to right, Rich Page, Steve Waldee, Ron and Ryan Wood.

E. E. B. himself recounted the history of this instrument in the publication of his Milky Way photographs. Willard was not the maker, but the dealer for large portrait wet-plate cameras that soon replaced the old Daguerrotype process. In 1849, one Charles F. Usner in New York City actually constructed the lens, a doublet (in Barnard's precise calculations) consisting of a front element of exactly 5.85 inches aperture with solar focus of 42.59 inches, and rear element of 6.73 inches diameter, focal length of 70.2 inches. Together, their cone of focused light fell exactly 778.9 millimeters distant onto the photographic plate. The scale of image obtained was 1.81 degrees per inch. If one were self-taught Edward Barnard, Bachelor of Science, writing in the Publications of the Lick Observatory, it would not do to round off to tenths of an inch or centimeters! (148) Today a typical 35-millimeter film camera sports a lens of but 2 inches of aperture; in Matthew Brady's time the slow wet collodion plates required exposures of several minutes' duration of subjects bathed in bright sunlight and magnified by huge lenses. Young Ed Barnard was all too familiar with the practices of the old photographers, with their stultifying poses and dangerous chemicals. But when the ''sensitive'' dry plates were introduced a few decades later, the gargantuan lenses -- such as Usner's -- became obsolete for commercial purposes, and were now available as relatively cheap surplus. 

Barnard recalled his slightly stilted and proper style that, 

   "The advent